A novel high-conversion-ratio bidirectional three-phase DC-DC converter

A novel high-conversion-ratio bidirectional three-phase DC-DC converter is proposed in this paper, which features not only low switch voltage and current stresses, but also automatic voltage balancing and current sharing ability without adding extra circuit or control method. Both total current ripple of the inductors and total voltage ripple of the capacitors are reduced by using interleaving technology. The proposed converter is suitable for fields of renewable energy, electric vehicles, energy storage systems and so on. The proposed topology can achieve three times the conversion ratio of the traditional three-phase DC-DC converter by only adding two capacitors. High voltage conversion ratio can be achieved with a moderate duty cycle which can avoid the extreme working condition existed in the traditional boost converter. Control method, operating principle, voltage conversion ratio, characteristics of automatic voltage balancing and current sharing, voltage and current stresses current and voltage ripples are analyzed in more detail. Finally, feasibility and superiority of the proposed converter are verified by software simulation and prototype experiment.